Patient interface assembly for respiratory therapy

ABSTRACT

A patient interface assembly includes a housing that defines an inlet port and an outlet port. A jet pump receives pressurized gas flow from the inlet port and delivers the gas flow to the outlet port. A nebulizer is fluidly coupled to the outlet port and positioned to introduce medication into the gas flow and deliver medicated gas flow to a patient.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application is a continuation of U.S. patent application Ser. No.12/274,083, filed Nov. 19, 2008, U.S. Pat. No. 8,931,478, entitled,“PATIENT INTERFACE ASSEMBLY FOR RESPIRATORY THERAPY,” which claims thebenefit of U.S. Provisional Patent Application No. 60/988,977, filed onNov. 19, 2007, entitled, “RESPIRATORY THERAPY SYSTEM WITHELECTROMECHANICAL DRIVER,” the disclosures of which are incorporatedherein by reference in its entirety.

BACKGROUND

The present disclosure relates to respiratory therapy systems anddevices. More particularly, it relates to patient interface assembliesconfigured to couple to respiratory therapy systems for delivery ofmedication.

A wide variety of respiratory therapy devices are currently availablefor assisting, treating, or improving a patient's respiratory health.For example, positive airway pressure (PAP) has long been recognized tobe an effective tool in promoting bronchial hygiene by facilitatingimproved oxygenation, increased lung volumes, and reduced venous returnin patients with congestive heart failure. More recently, PAP has beenrecognized as useful in promoting mobilization and clearance ofsecretions (e.g., mucous) from a patient's lungs. In this regard,expiratory positive airway pressure (EPAP) in the form of high frequencyoscillation (HFO) of the patient's air column is a recognized techniquethat facilitates secretion removal. In general terms, HFO reduces theviscosity of sputum in vitro, which in turn has a positive effect onclearance induced by an in vitro simulated cough. HFO can be deliveredor created via a force applied to the patient's chest wall (i.e., chestphysical therapy (CPT)), or by applying forces directly to the patient'sairway (i.e., breathing treatment, such as high frequency airwayoscillation). Many patients and caregivers prefer the breathingtreatment approach as it is less obtrusive and more easily administered.To this end, PAP bronchial hygiene techniques have emerged as aneffective alternative to CPT for expanding the lungs and mobilizingsecretions.

Various HFO treatment systems are available for providing therespiratory therapy (high frequency intrapulmonary percussive therapy)described above (as well as other therapies and/or ventilation). Ingeneral terms, the high frequency intrapulmonary percussive (HFIP)system includes a hand-held device establishing a patient breathingcircuit to which a source of positive pressure gas (e.g., air, oxygen,etc.) is fluidly connected. In this regard, the system further includesa driver unit that acts upon the supplied positive pressure gas,creating an oscillatory pressure profile or otherwise effectuateintermittent flow of gas into the patient breathing circuit, and thuspercussive ventilation of the patient's lungs. With this approach, thepatient breaths through the breathing circuit's mouthpiece (or mask),that in turn delivers the generated high-flow, “mini-bursts” of gas tothe patient's airways. The pulsatile percussive airflow periodicallyincreases the patient's airway pressure.

Current HFO treatment systems can also be used with a nebulizer todeliver aerosolized medication to patients. The nebulizer can be fluidlycoupled to the driver unit to deliver medicated gas to patients throughthe patient interface circuit. Conventional configurations of patientinterface circuits entrain medication within a device with ambient airto deliver the medicated gas to the patient. These configurations cancontribute to medication “knock down”, wherein build-up of medicationwithin the device increases and the amount of medication delivered tothe patient is reduced. Thus, a need exists for improved respiratorytherapy systems, in particular patient interface assemblies that delivermedication to a patient.

SUMMARY

Concepts presented herein relate to a patient interface assembly fordelivering respiratory therapy to a patient. The assembly includes ahousing defining an inlet port and an outlet port. The inlet port iscoupleable to a driver unit to receive pressurized gas flow produced bythe driver unit. A jet pump disposed within the housing receivespressurized gas flow from the inlet port and delivers the pressurizedgas flow to the outlet port. A nebulizer is fluidly coupled to theoutlet port to receive pressurized gas flow, introduce medication intothe gas flow and deliver medicated gas flow to the patient.

Aspects of the patient interface assembly can further be incorporatedinto a system and method to provide respiratory therapy. Additionally,other aspects can be added, removed and/or modified to the assembly. Forexample, the housing can include one or more of an entrainment port,exhalation port, nebulizer port and a pressure port. Further, the jetpump can be slidable within the housing and include an entrainmentregion, a throat region and/or an expansion region.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a respiratory therapy system.

FIGS. 2-14 are schematic illustrations of other respiratory therapysystems.

FIGS. 15 and 16 are illustrations of a first embodiment of a patientinterface device.

FIG. 17 is an illustration of a second embodiment of a patient interfacedevice.

FIGS. 18-20 are illustrations of a third embodiment of a patientinterface device.

FIG. 21 is an illustration of a connector having multiple ports forfluidly coupling a driver unit to a patient interface device.

DETAILED DESCRIPTION

FIG. 1 is a schematic illustration of one embodiment of a respiratorytherapy system 20 including a driver unit 22 and a patient interfacedevice 24 that serves as a patient interface circuit, establishing abreathing conduit to and from a patient 25 during use. In particular,the breathing conduit extends to an airway of the patient 25 (e.g.mouth, nasal sinuses). In one embodiment, the breathing conduit to theairway can be established with patient 25 through intubation.Additionally, if desired, the system 20 can be used with or without aventilator. Details of the various components are described below. Ingeneral terms, however, the driver unit 22 is adapted for fluidconnection to a source 26 (referenced generally) of pressurized gas(e.g., air, oxygen, etc.), and includes a controller 28 that controlsoperation of one or more electronic valves fluidly disposed between aninlet line 30 and an outlet line 32. More particularly, pressurized gasflow from the source 26 at the inlet line 30 is acted upon by theelectronic valve(s) to create or supply a desired flow/pressure to thepatient interface device 24 via the outlet line 32.

As described below, the driver unit 22 can include a number of differentcomponents or features, and the system 20 can include other, optionalcomponents, such as a nebulizer 34. One type of nebulizer that can beused in system 20 is an AirLife® Brand Misty Max 10™ nebulizer,available from Cardinal Health of Dublin, Ohio. In the case of use ofnebulizer 34, an auxiliary line 35 extends from the driver unit 22 tothe nebulizer 34. Controller 28 can be used to operate drive unit 22 tosupply a desired flow/pressure to the nebulizer 34 via the auxiliaryline 35. Regardless, the system 20 is capable of providing highfrequency pressure pulses to the patient (e.g., percussive therapy) viaoperation of the driver unit 22, and offers a larger range ofdeliverable frequencies and pressures as compared to conventional,pneumatic valve-based driver units. A patient pressure line 36 can beprovided to fluidly connect the patient interface device back to thedriver unit 22 such that pressure within the patient interface device 24can be measured and/or monitored. Controller 28 can be configured tocontrol delivery of air to the patient 25 based on pressure measured inthe patient interface device 24. Driver unit 22 can include furtherelectronic valve(s) that operate to, for example, purge patient pressureline 36 and thus prevent excessive build up of fluids within the patientpressure line 36, allow auto zeroing of a pressure sensor, etc. In oneembodiment, driver unit 22 can be connected to a central processingstation, for example a nurse's station, to deliver information regardingoperation of driver unit 22 and/or other information associated with thepatient.

As illustrated with more particularity in FIG. 2, the driver unit 22 caninclude a number of other components in addition to the controller 28,each of which are maintained in or by a portable housing 37. Forexample, with the one configuration of FIG. 2, the driver unit 22includes an electronic valve 40 (e.g. a proportional solenoid valve)configured to act upon supplied pressurized gas in creating continuoushigh frequency pressure pulses. Alternatively, multiple on-off typesolenoid valves can also be used to supplement and/or replace electronicvalve 40. The electronic valve 40 can also be configured to selectivelyact upon supplied pressurized gas to effectuate delivery of a baselinepressure, positive airway pressure (PAP), continuous positive airwaypressure (CPAP), etc. Other forms of positive airway pressure can alsobe used, such as bilevel PAP (BiPAP), which provides two levels ofpressure. In any event, PAP is controlled from a manifold sensor indriver unit 22, while CPAP is controlled from a patient pressure sensorfluidly coupled to patient pressure line 36. The electronic valve 40 isfluidly connected between the inlet line 30 and the outlet line 32, andis electronically coupled to the controller 28. Thus, the controller 28controls operation of the electronic valve 40 based upon programmingmaintained by the controller 28 (e.g., software and/or hardware). Inthis regard, the controller 28 can control delivery of power to theelectronic valve 40 (as well as other components described below), witha power supply (not shown) being electrically coupled to the controller28. The power supply can take a variety of forms, such as a batterymaintained in the housing 37, a power cord for connection to aconventional wall power source, etc.

The electronic valve 40 includes or defines an inlet side 42 and anoutlet side 44. Inlet side 42 is fluidly connected to an internal inletline 46 that is internal to housing 37, whereas the outlet side 44 isfluidly connected to an internal outlet line 48 internal to housing 37.Internal inlet line 46 is fluidly coupled to inlet line 30 and internaloutlet line 48 is fluidly coupled to outlet line 32. With thisconstruction, then, gas flow provided to the inlet line 30 is deliveredto the electronic valve 40. The electronic valve 40 can assume a varietyof forms appropriate for introducing or creating high frequency pressurepulses when acting upon pressurized gas flow from the source 26. Moreparticular, with embodiments in which the system 20 is adapted for usewith “standard” source gas pressures provided at hospitals (e.g., oxygenor air maintained at a pressure in the range of 40-70 psi), theelectronic valve 40 is configured to repeatedly open and obstruct aninternal orifice (i.e., permit and prevent passage of gas therethrough)in response to signals from the controller 28 to create a pulse pressureflow over a large range of frequencies and pressures. For example, withsome configurations, the electronic valve 40 is capable of generatingpressure pulses at frequencies in the range of 1-25 Hz. Otherfrequencies can also be achieved, such as below 1 Hz and/or greater than25 Hz (for example, as high as 30 Hz or 40 Hz).

As compared to conventional pneumatic shuttle valve-based driver units,the electronic valve 40 of the present disclosure provides a markedadvantage in terms of more precise control and increased operationalfrequency and pressure ranges. Additionally, pneumatic valves requirecharging, thereby providing a large initial pressure pulse to thepatient. Further, by electronically controlling the electronic valve 40,any change in gas pressure at the source 26 has little or no effect onthe pulse profile generated by the electronic valve 40, therebydelivering consistent therapy while avoiding unexpected high pressures.Even further, the electronically-controlled valve 40 will not “stall”during an oscillatory pressure mode of operation, thus avoiding theproblematic, unexpected delivery of high constant pressure to a patientfound with available pneumatic valve driver units. In addition, bymonitoring parameters within driver unit 22, driver unit 22 can increasesafety by preventing undesirable situations and/or provide alarms toalert a caregiver. The electronic valve 40 can also be provided foreffectuating a continuous, positive airway pressure when desired.Electronic valve 40 can further be configured to reduce dead volume. Inone particular embodiment, dead volume is reduced to less than two cubicinches.

In addition to the electronic valve 40 described above, the driver unit22 includes an optional purge electronic valve 50 that is electronicallycoupled to, and controlled by, the controller 28. In one embodiment,purge electronic valve 50 can be a solenoid valve. With the oneconstruction of FIG. 2, the purge electronic valve 50 is fluidlyconnected to the interior inlet line 46 in parallel with the electronicvalve 40 and serves to purge patient pressure line 36 leading from thepatient interface 24 to the driver unit 22. The purge electronic valve50 has an inlet side 52 fluidly connected to the interior inlet line 46,and an outlet side 54 fluidly connected to a purge line 56. The purgeline 56 is fluidly coupled to patient pressure line 36 such that purgeelectronic valve 50 can be operated to clear patient pressure line 36 offluids that may build up, in particular liquid and/or other particlesexhausted from the patient 25.

To this end, a patient sensor autozero electronic valve 60 (e.g. asolenoid valve) can be provided to work cooperatively with the purgeelectronic valve 50. Autozero electronic valve 60 is electronicallycoupled to, and controlled by, the controller 28 and includes an inletside 62, an outlet side 64 and an exhaust side 66. During normaloperation, autozero electronic valve 60 is in a normally “open”position, allowing fluid to flow from patient pressure line 36 to apatient pressure sensor 67, which is discussed in more detail below.When patient pressure line 36 is purged, autozero electronic valve 60 isclosed and patient pressure sensor 67 is fluidly coupled to a vent line68, which is open to ambient (e.g., fluidly open to an exterior ofhousing 37). Next, purge valve 50 is opened, allowing patient pressureline 36 to be purged. Once patient pressure line 36 has been purged, andpurge valve 50 is closed, autozero electronic valve 60 is opened as innormal operation.

Autozero electronic valve 60 can also be utilized to calibrate patientsensor 67, for example upon start up of system 20. To calibrate patientpressure sensor 67, autozero electronic valve 60 is closed such thatpressure sensor 67 should read ambient pressure, as it is fluidlyconnected to ambient via vent line 68. Otherwise, patient pressuresensor 67 can be adjusted to a known reference ambient pressure. Ifdesired, patient pressure line 36 can be purged during this adjustment.After calibration, autozero electronic valve 60 is opened as in normaloperation.

An additional, optional feature of the driver unit 22 is an auxiliaryvalve 70. The auxiliary valve 70 can be electronic (e.g. solenoid) orpneumatic. The auxiliary valve 70 defines an inlet side 72 and an outletside 74, and is electronically coupled to, and controlled by, thecontroller 28. The inlet side 72 is fluidly connected to the interiorinlet line 46, in parallel with the electronic valve 40 and the purgeelectronic valve 50. However, the outlet side 74 is not connected to theinterior outlet line 46. Instead, the outlet side 74 is fluidlyconnected to interior auxiliary line 78 that extends within the housing37 for selective coupling to the auxiliary line 35. With thisconstruction, then, the auxiliary valve 70 controls gas flow to thenebulizer 34, and thus can be referred to as the “neb flow valve”. Thenebulizer 34 is described in greater detail below. In general terms,however, in a nebulizer mode of operation, the controller 28 operatesthe neb flow valve 70 to an open state, thereby permitting gas flow tothe nebulizer 34.

As shown in FIG. 2, the electronic valve 40, the purge electronic valve50, the autozero electronic valve 60 and the neb flow valve 70 can beprovided as part of, or connected to, a manifold 80. The manifold 80effectively establishes three, parallel gas flow channels from theinterior inlet line 46, with the electronic valve 40 permitting gas flowto the interior outlet line 48, the purge electronic valve 60 permittinggas flow to the feedback line 36 and with the neb flow valve 70permitting gas flow to the auxiliary line 35 (via operation of thecontroller 28) as described above.

An optional volume chamber 88 can be provided along the interior inletline 46 “upstream” of the valve 40. The volume chamber 88 acts as anaccumulator or reservoir for storing fluid from inlet line 30. Thus,volume chamber 88 can reduce drop in pressure upon opening one or moreof the valves 40, 50 and 70. For example, upon opening the purgeelectronic valve 50, fluid in volume chamber 88 can be utilized toreduce pressure drop from volume chamber 88 to inlet side 52 of purgeelectronic valve 50.

To account for possible pressure fluctuations from the gas source 26,the driver unit 22 can further include an optional pressure regulator 90along the interior inlet line 46 “upstream” of the valve 40. Thepressure regulator 90 can be a mechanical or electronically controlleddevice, configured to regulate incoming pressurized gas flow down to adesired pressure, thus maintaining a consistent therapeutic output fromthe system 20 regardless of the pressure provided at the source 26. Assuch, the driver unit 22 will generate consistent therapeutic outputsfrom hospital-to-hospital, it being recognized that the actual source 26pressure will likely vary from location-to-location.

An additional optional feature provided with the driver unit 22 of FIG.2 is a filter 100 fluidly connected to the interior inlet line 46“upstream” of the valve 40. The filter 100 can assume a variety offorms, and is generally configured to remove debris or moistureentrained in the gas flow from the source 26. In some embodiments, thefilter 100 is a water trap-type, and is fluidly located upstream of thepressure regulator 90.

If desired, driver unit 22 can further include an input electronic (e.g.solenoid) valve 102 that defines an inlet side 104 and an outlet side106. Input electronic valve 102 is fluidly connected to interior inletline 46 “upstream” of the filter 100. Additionally, input electronicvalve 102 is electronically coupled to, and controlled by, controller28. Input electronic valve 102 can be operated as an emergency “shutoff”valve and be operated to a closed state in instances where an internalpressure above a preset limit exists or a patient pressure exceeds apredefined value, closing flow to driver unit 22. The input electronicvalve 102 is in the “normally closed” position and will selectivelyoperate to permit fluid to pass from inlet side 104 to outlet side 106upon direction from controller 28. When driver 22 is not in operation,input electronic valve 102 is closed. As a result, risk of potentialbuild up of pressure within manifold 80 and/or housing 37 can bereduced.

In a further embodiment, an electronic vent valve 108 and a vent line109 can be fluidly coupled between interior inlet line 46 and ambient toprevent pressure build up in interior inlet line 46 by opening ventvalve 108. Vent valve 108 can be an electronic valve that iselectronically coupled to, and controlled by, controller 28. Vent valve108 defines an inlet side 112 and an outlet side 114. Inlet side 112 isfluidly coupled to interior inlet line 46 and outlet side 114 is fluidlycoupled to vent valve 109. The vent valve 108 is in the “normally open”position, allowing flow from inlet side 112 to outlet side 114. Duringnormal operation of driver unit 22, vent valve 108 will be operated tothe closed position by controller 28. In yet another embodiment,electronic valve 40, purge electronic valve 50 and/or neb flow valve 70can be operated to reduce pressure in interior inlet line 46.

With some constructions, the driver unit 22 is adapted for acting upongas from one or more different sources 26. For example, the source canbe oxygen, pressurized air from a compressor, fractional oxygen from ablender, etc. Additionally, these sources may have several differenttypes of connectors based on source type, standards for a particularcountry, etc. With this in mind, the inlet line 30 is optionally fluidlyconnected to one or more inlet connectors 110, with each of theconnectors 110 configured for fluid connection to a separate supplysource 26. For example, one of the connectors can establish a fluidconnection to a source of pressurized oxygen, whereas another of theconnectors can establish a fluid connection with a source of pressurizedair, thereby allowing for blending of gas within the driver unit 22. Inaddition, connectors can be adapted to be coupled to a blender thatdelivers fractional inspired oxygen. In the embodiment illustrated, onlya single one of the connectors 110 is provided and connected to inletline 30. Connector 110 is then fluidly coupled to interior inlet line46.

As referenced above, the controller 28 controls operations of the valves40, 50, 60, 70, 102 and 108. In this regard, in some embodiments, thecontroller 28 utilizes feedback information in controlling operations.With this in mind, the driver unit 22 further includes an optionalmanifold pressure sensor 120 fluidly connected to the interior outletline 48. The manifold pressure sensor 120 can assume a variety of formscapable of sensing gas pressure within the interior outlet line 48.Regardless, the manifold pressure sensor 120 is electronically coupledto the controller 28, signaling information indicative of the pressuresensed in the outlet line 32, and thus provides closed-loop feedback tothe controller 28. In one example, manifold pressure sensor 120 is usedto monitor whether a desired PAP level is being provided to the patient.

As mentioned above, patient pressure sensor 67 can also form and serveas an information source to controller 28. The patient pressure sensor67 can assume a variety of forms, and is fluidly connected to thepatient interface device 24 for sensing pressure within the patientinterface device 24 through patient pressure line 36 and autozeroelectronic valve 60. As described in greater detail below, the patientinterface device 24 can be configured to provide a convenient port forreceiving patient pressure line 36 that in turn is fluidly coupled tothe patient pressure sensor 67 (as retained by the housing 37).Regardless, the patient pressure sensor 67 is electronically coupled tothe controller 28, and signals information indicative of a sensedpressure at the patient interface device 24. In one example, patientpressure sensor 67 is used to monitor whether a desired CPAP setting isbeing provided to the patient. Other parameters, such as flow or pulsevolume delivered to the patient, can also be used to provide feedback tocontroller 28, if flow measuring or spirometry means are integrated intodriver unit 22.

The driver unit 22 further optionally includes one or more displaysystems 130 for displaying information to a caregiver. In one example,display system 130 can be a liquid crystal display. The displaysystem(s) are electronically coupled to, and controlled by, thecontroller 28, and can include a graphical user interface (GUI) 132. Asdescribed below, the GUI 132 can be operated to display variousperformance information (e.g., graphical depiction of a current pulseprofile, minimum and maximum pressures, etc.).

The driver unit 22 includes a user input device (or interface) 140 thatis electronically coupled to the controller 28. The user interface 140serves as a selection indicator, affording the caregiver the ability toselect a desired mode of operation as described below. Thus, the userinterface 140 can assume a wide variety of forms, including mechanical(e.g., control knob) and/or visual (e.g., touchpad device) devices.

During use of the system 20, the inlet line 30 is fluidly connected tothe supply source(s) 26 via the appropriate connector(s) 110. Thepatient interface device 24 is provided to the caregiver separate fromthe driver unit 22. Various possible configurations of the patientinterface device 24 are described below. In general terms, however, thepatient interface device 24 can be a disposable, hand-held product,including an inlet end 150 configured for fluid coupling to the outletline 32 otherwise extending from the housing 37, and an outlet end 152through which the patient breathes (with the outlet end 152 beingconnectable to (or forming) a patient breathing component such as amouthpiece or mask). In one embodiment, outlet line 32, auxiliary line35 and patient pressure line 36 are each formed of tubing that can beprovided with the patient interface device 24.

Each of the lines 32, 35 and 36 can terminate at a connector piece 156(referenced generally) sized for engagement within a correspondingconnector port 158 of the driver unit 22. For example, the connectorport 158 can be carried by the housing 37, and can establish fluidconnections to the outlet line 32, the patient pressure line 36, and/orthe auxiliary line 35 such that only a single connective step isrequired of the operator (i.e., insertion of the connector piece 156into connector port 158). Alternatively, connector port 158 can beformed integral with the housing and/or manifold. In any event, theconnector piece 156 can hold each of the lines 32, 25 and 36 in fixedrelation for simple fluid connection to the driver unit 22. Furthermore,connector piece 156 can include a quick-release mechanism for easilysecuring and releasing connector piece 156 to and from connector port158.

Connector piece 156 can further include an identifier stored on any typeof storage medium 160, such as an RFID tag, that indicates capabilitywith the driver unit 22. To this end, the driver unit 22 can furtherinclude a device 162 to receive information from storage medium 160,such as an RFID tag reader, electrically coupled to the controller 28.Storage medium 160 can include further information that can betransmitted to controller 28 through device 162. For example, storagemedium 160 can be associated with a particular predetermined therapyprotocol and thus controller 28 can be operated in conjunction with thedesired therapy protocol. Additionally, other information can be storedon storage medium 160, such as patient information, compatibilityinformation, etc. Alternatively, any other type of communication meanscan be utilized to deliver information associated with the patientinterface device 24 to the driver unit 22. One example communicationmeans that can be used is a contact serial interface such as 1-Wire®Serial Memory Products, provided by Maxim Integrated Products, Inc. ofSunnyvale, Calif. In this case, potential interference of radiofrequency signals can be eliminated due to direct contact between hostand slave hardware that creates the interface.

Regardless, with the patient interface device 24 fluidly connected tothe outlet line 32 and, where provided, the patient pressure sensor 67(via the patient pressure line 36), the caregiver then operates thedriver unit 22 to deliver a respiratory therapy to the patient. In thisregard, the driver unit 22 optionally offers at least six modes ofoperation, including an autozero mode, a percussive mode, a baselinemode, a positive airway pressure (PAP) mode, a purge mode and anebulizer mode. Each of these modes can be implemented independent ofthe other, or two or more of the modes can be effectuatedsimultaneously. Each mode of operation is described in greater detailbelow. One or more of the modes can also be implemented by controller 28as defined in a pre-defined protocol that can easily be implemented by acaregiver.

As a starting point, the driver unit 22 is optionally configured suchthat the electronic valves 40, 50, 70 and 102 default to a normally“closed” state in which gas flow through the respective valve 40, 50, 70and 102 does not occur. The electronic valves 60 and 108 default to anormally “open” state in which gas flows through the valves 60, 108. Inparticular, outlet side 64 of valve 60 is fluidly coupled to inlet side62 and outlet side 114 of valve 108 is fluidly coupled to inlet side112. When system 20 is powered “on”, the autozero mode can begin so asto calibrate patient pressure sensor 67. In autozero mode, autozeroelectronic valve 60 is closed, allowing patient pressure 67 to readambient pressure since patient pressure sensor 67 is coupled to ambientvia vent line 68. Based on the reading of patient pressure sensor 67,adjustments can be made such that patient pressure sensor 67 registers aknown ambient pressure. Once patient pressure sensor 67 is adjusted asdesired, autozero electronic valve 60 is opened.

Upon receiving an indication from a caregiver (via the user input 140)that a percussive mode is desired, the controller 28 operates theelectronic valve 40 to rapidly open and close, thus imparting pressurepulses into the gas flow from the inlet line 30 to the outlet line 32.In this regard, the electromechanical configuration of the electronicvalve 40 allows the controller 28 to achieve precise control over thedelivered pressure pulse profile, which can be based off of readingsfrom manifold pressure sensor 120. Thus, the pulsed gas flow deliveredto the patient interface device 24, via the outlet line 32, can have oneof many different frequencies and/or pressures commensurate with theoperational capabilities of the electronic valve 40. If desired, thebaseline mode can supplement the pulsed gas flow to maintain lungrecruitment. As a point of reference, different frequencies andpressures have different effects on a patient. For example, frequenciesaround 20 Hz have been found to lower the viscosity of the mucous,whereas frequencies in the range of 8-15 Hz are commensurate with thenormal cilia beat frequency range and thus work to mobilize secretions.Frequencies in the range of 2-5 Hz have been found to expand the lungsand deliver oxygen to the alveoli, as well as stimulate a “mini-cough”and shear mucous. Thus, depending upon a desired therapeutic result, thecaregiver can (via the user interface 140) effectuate a desiredprotocol/frequency.

In some instances, the caregiver is aware of a desired protocol (e.g.,in terms of pressure and/or frequency), and can enter the desiredvalue(s) at the user interface 140 for subsequent implementation by thecontroller 28. With other embodiments, the controller 28 ispre-programmed with one or more potentially applicable protocolsettings. For example, the controller 28 can include a memory in which alibrary of protocol settings is maintained. Selection of a protocol canbe based on several factors. In one embodiment, if flow sensing and/orspirometry means are employed, protocol selection can be based onmeasurements obtained by these means. Upon selection of a desiredprotocol at the user interface 140, the controller 28 automatically“loads” the predetermined settings such that operation of the system 20requires less training and easier set-up by the caregiver as compared toconventional driver units. For example, one predetermined desiredprotocol could comprise two minutes of PAP mode, followed by two minutesof 20 Hz percussive therapy, followed by two minutes of 2 Hz percussivetherapy, etc.

Alternatively, or in addition to, storage medium 160 (e.g. an RFID tag)can store a particular desired setting that can be read by device 162(e.g. an RFID reader) and communicated to controller 28. Further, thepre-programmed features ensure that consistent and uniform therapy willbe provided to the patient independent of caregiver knowledge of thetherapy. Due to the consistent and uniform therapy delivered, thecaregiver can identify if changes in the patient airway has occurredgiven changes in patient pressure sensor 67 (e.g. increased lungrecruitment). This is in direct contrast to current devices/drivers onthe market that are not intuitive to set up or use. Some require needlevalves that are manipulated by the caregiver to control the profile ofthe pulse. While attempting to change intensity in a pneumatic system,frequency will also change, making it difficult to independently alterintensity and frequency. Significant, unexpected changes in theresultant pulse profile may occur even when making only a smalladjustment in the position of the needle valve. This makes it difficultfor existing devices to deliver consistent, expected therapy.

In addition or as an alternative to the pre-programmed settings, thecontroller 28 can be programmed by the caregiver to store one or moredesired therapy protocols. These programs can be entered by thecaregiver or the caregiver's colleague (such as in a hospital setting)to ensure the exact same treatment procedures are followed throughoutthe hospital and amongst all of the respiratory therapists using thedriver unit 22. If desired, this information can be directly stored on astorage medium and tailored as requested during manufacturing and/orassembly of driver unit 22. For example, different parameters can beutilized when preparing a system for pediatrics as opposed to adults,allowing for different therapy and/or alarm settings.

In addition to operating the electronic valve 40 based upon user-enteredand/or predetermined settings, in some embodiments, the controller 28 isfurther programmed to perform an example routine in which a resonantfrequency (where the most effective therapy is likely to occur) of thepatient's lungs is “located.” More particularly, the example routineincludes the controller 28 operating the electronic valve 40 toinitially generate higher frequency pulse rates (e.g., 20 Hz) andgradually decrease to a lower rate (e.g., 2 Hz). The process is thenrepeated at incrementally higher pressures. The rate can also decrease,if desired, by starting at a high frequency pulse rate and decreasing toa lower rate.

Throughout the example routine, the patient is monitored for chestwiggle, as is information signaled from the pressure sensors 67, 120, todetermine the pulse rate frequency that best fits the resonantfrequency, or “sweet spot,” for a particular patient. In one embodiment,an accelerometer can be coupled to the patient's chest and provide asignal indicative of chest movement. This chest movement signal can bemonitored based on the rate of frequency pulses delivered to identify anoptimal frequency.

The percussive mode of operation can be supplemented by the baselinemode of operation. The baseline mode provides a desired pressure,wherein electronic valve 40 partially obstructs flow from interior inletline 46 to interior outlet line 48. The pressure is provided to keeppatient airways open during delivery of percussive therapy (e.g. betweenbursts of air flow).

As with the procedures described above, the controller 28 can bepre-programmed or preset with one or more therapy protocols that includeoperation of the electronic valve 40 in delivering PAP pressure to thepatient. One example, non-limiting protocol program can include: 1)running the PAP mode low pressure for five minutes (i.e., the electronicvalve 40 open); 2) operate the electronic valve 40 at 20 Hz, with lowpressure for three minutes; 3) operate the electronic valve 40 togenerate percussive pulses at a frequency of 2 Hz with low pressure forthree minutes; and 4) operate the electronic valve 40 at a frequency of5 Hz with high pressure for five minutes. A wide variety of otherprotocols are equally available.

Where a PAP therapy is desired, the controller 28, upon receiving acorresponding caregiver selection of the PAP mode at the user interface140, operates the electronic valve 40 to “open” a desired extent. Inthis regard, the pressure desired for the PAP therapy can be selected(or pre-programmed) by the user, with the controller 28 monitoringinformation from the manifold pressure sensor 120 to determine whetherthe effectuated electronic valve 40 setting is achieving the desiredpressure. Alternatively, or in addition to, CPAP, Bi-PAP, etc. therapycan be delivered based on information received from patient pressuresensor 67.

The purge mode can be performed in conjunction with the autozero modedescribed above. Additionally, the purge mode can be performedindependent of the autozero mode. To purge patient pressure line 36,autozero electronic valve 60 is moved to a closed position, such thatflow is shut off from inlet side 62 to outlet side 64. At this point,patient pressure sensor 67 is fluidly coupled to vent line 68, whichexits the portable housing 37. Thus, patient pressure sensor 67 readsatmospheric pressure and its feedback to controller 28 can be delayedand/or patient pressure sensor 67 can be adjusted as discussed withrespect to the autozero mode. The purge electronic valve 50 is thenopened so that flow from inlet line 30 is used to purge patient pressureline 36 of liquid and/or other build up. After patient pressure line 36has been purged, purge electronic valve 50 is closed and then autozeroelectronic valve 60 is moved to the open position, allowing flow topatient pressure sensor 67.

In the nebulizer mode, the nebulizer 34 is fluidly connected to the nebflow valve 70 (via the auxiliary line 35) as well as to the patientinterface device 24. For example, the single connector 156 mentionedabove can establish the necessary fluid connection to driver unit 22through connector port 158. In some embodiments, the patient interfacedevice 24 and the nebulizer 34 are constructed such that the nebulizer34 fluidly connects to the outlet end 152 of the patient interfacedevice 24, with the nebulizer 34 being provided apart from the driverunit 22. Regardless, by locating the nebulizer 34 “downstream” of thepatient interface device 24, aerosolized medication generated by thenebulizer 34 does not pass through the patient interface device 24,thereby significantly reducing the possibility for aerosol knock-downwithin the geometry of the patient interface device 24. For example,configurations with the nebulizer 34 located “downstream” of the patientinterface device 24 can deliver more than five times as much inhaledrespirable mass (e.g. aerosolized medication) to a patient compared toconventional patient interface designs.

With the nebulizer 34 fluidly connected as described above, thecontroller 28, upon receiving a corresponding selection by the caregiverat the user interface 140, operates the neb flow valve 70 to permit gasflow to the auxiliary line 35, and thus to the nebulizer 34. In thisregard, the controller 28 can maintain the electronic valve 40 in aclosed state such that only nebulizer therapy is delivered to thepatient. Alternatively, and as desired by the caregiver, the electronicvalve 40 can simultaneously be operated (with the neb flow valve 70 atleast partially open) to deliver aerosolized medication to the patientin conjunction with a percussive, percussive with baseline and/or PAPtherapy, and/or during a predefined protocol.

During operation of the system 20 in delivering percussive, PAP ornebulizer therapy, the controller 28 is programmed to maintain desiredoutput from the electronic valve 40 via information received from thepatient pressure sensor 67 and/or the manifold pressure sensor 120. Themanifold pressure sensor 120 provides feedback allowing the controller28 to monitor the output of the electronic valve 40, thus creating aclosed-loop system that enables the controller 28 to incrementallyadjust operation of the valve 40 as necessary. This feature, in turn,assures that the desired or correct pulse pressure (or baseline pressureif in baseline mode) is consistently and constantly being delivered tothe patient.

The patient pressure sensor 67 monitors the pressure being delivered tothe patient. In instances where the controller 28 “determines” that thesensed patient pressure and/or manifold pressure exceeds a predeterminedvalue, the controller 28 can automatically initiate operation of theelectronic valves 40, 70 and/or 102 to a closed state. Additionally,pressure delivered to a patient can be adjusted based on pressure sensedby patient pressure sensor 67. In one example, patient inspiratory andexpiratory phases of breathing can be detected using patient pressuresensor 67 and/or spirometry means that sends information to thecontroller 28. During a percussive mode of operation, percussive therapycan be delivered during the patient inspiratory phase by operatingelectronic valve 40 to deliver percussive pulses during the inspiratoryphase. If a maximum patient pressure is known (e.g. as prescribed by aphysician), electronic valve 40 can further be operated based on themaximum patient pressure and the inspiratory/expiratory phases.Alternatively, spirometry means can be used to detect patient breath andalter the delivery of therapy during either inspiratory or expiratoryphased to maximize a desired effect.

Other measurement devices can also be employed to deliver information tocontroller 28 for display and/or to control operation of driver unit 22.For example, a spirometer can be utilized to measure a volume of airinspired and/or expired by the patient. The spirometer can be integratedinto patient interface device 24 and utilized to determine patientprogress (e.g., a higher volume of air expired by the patient mayindicate patient improvement) due to the fact that a section of the lunghas been cleared and/or recruited.

As indicated above, the display system 130 can be operated by thecontroller 28 to display various information to the caregiver asdesired. In addition to displaying various operational control settings(e.g., operational mode, selected pressure(s) and/or frequency), thecontroller 28 can determine and display information indicative of orrelating to the actual pressure or gas flow being delivered to thepatient. For example, the controller 28 can be programmed to recordpressures sensed by the patient pressure sensor 67 and calculateinformation, such as minimum, mean, maximum, and/or trending pressure,with this information being displayed on the display system 130. Thedisplay protocol can vary, and in some embodiments the controller 28 isprogrammed to update the displayed information periodically (e.g., onceevery second), with the maximum pressure recorded over the previous timeperiod (e.g., second) of data acquisition.

The driver unit 22 can also include various optional alarm featuresoperated by the controller 28. For example, if a pressure is detected atthe manifold pressure sensor 120 and/or the patient pressure sensor 67that exceeds a preset pressure limit, the controller 28 is programmed tooperate the alarm (e.g., audible, visual) to alert the caregiver and toimplement a step-down therapy protocol and optionally closing theelectronic valves 40, 70 and 102. These alarms can be user adjustable toany type of setting for notification of events based on varioussituations (e.g., crossing an adjustable threshold).

The system 20 uniquely provides a plethora of features useful indelivering respiratory therapy to a patient. In other embodiments,features can be added, modified or eliminated as desired. For example,FIG. 3 provides a representation of a therapy system 170 where the purgeelectronic valve 50, the autozero electronic valve 60, the inputelectronic valve 102 and the vent electronic valve 108 have beeneliminated, along with volume chamber 88. Additionally, the therapysystem 170 includes multiple connectors 110 coupled to separate supplysources. One of the connectors can establish fluid connection with asource of pressurized oxygen whereas the other connector can establish afluid connection with a source of pressurized air. Still further, oneconnector could be coupled to a source of fractional inspired oxygen asgenerated by a gas blender. In yet a further embodiment, a gas blendercould be integrated into housing 37. In addition, the therapy system 170includes a secondary electronic valve 172 and a vent valve 174.

Secondary electronic valve 172 can be configured similar to electronicvalve 40 and is electronically coupled to, and controlled by, thecontroller 28. The electronic valve 40 and secondary electronic valve172 can serve to operate to deliver percussive therapy and PAP therapyseparately, such that one valve is used primarily for deliveringpercussive therapy and the other valve is used primarily for baselineand/or PAP therapy. Also, secondary electronic valve 172 can also beused to increase a range of intensity settings during percussive therapyas being operated in conjunction with the primary valve. Secondaryelectronic valve 172 can also be staggered with respect to electronicvalve 40 to allow for higher frequency settings of percussive therapydelivery.

In the embodiment illustrated, the secondary electronic valve 172 ispositioned in parallel with electronic valve 40 and neb flow valve 70.The secondary electronic valve includes an inlet side 176 fluidlycoupled to interior inlet line 46 and an outlet side 178 fluidly coupledto interior outlet line 48. In FIG. 3, electronic valve 40 is configuredto deliver percussive therapy while secondary electronic valve 172 isconfigured to deliver PAP therapy. Thus, controller 28 operates to driveelectronic valve 40 when percussive therapy is desired and operates todrive secondary electronic valve 172 when PAP therapy is desired.Further, controller 28 can operate the secondary electronic valve 172 inan open (or partially open) state during percussive operation of theelectronic valve 40 to provide percussive therapy in combination with abaseline pressure above ambient (e.g. the baseline mode).

The vent electronic valve 174 is electronically coupled to, andcontrolled by, the controller 28 and includes an inlet side 180 and anoutlet side 182. The vent electronic valve 174 serves as an emergency“dump” valve with the inlet side 180 fluidly coupled to the interioroutlet line 48 and the outlet side 182 fluidly connected to a vent line184. The vent line 184 is open to ambient. In instances where thecontroller 28 determines that an internal pressure above a preset limitexists, the vent electronic valve 174 is operated to an open state,allowing gas flow in the interior outlet line 48 to exhaust from thesystem 170 (and thus not be delivered to the patient interface device 24or the patient). Alternatively, the vent electronic valve 174 can belocated in any position along either interior inlet line 46 or outletinterior line 48 and operated in either a “normally open” or “normallyclosed” state. For example, the vent electronic valve 174 can be located“upstream” of the proportional solenoid valves 40, 172 (e.g., along theinterior inlet line 46 in a similar position as vent valve 108 in FIG.2). Even further, the vent electronic valve 174 can be in-line witheither of the interior inlet line 46 or the interior outlet line 48(i.e., the inlet side 180 and the outlet side 182 are fluidly connectedto the corresponding interior inlet line 46 or interior outlet line 48),operating in a normally “open” state. With this construction, upondetermining existence of an excessive pressure condition, the controller28 operates the electronic valve 174 to a closed state, thus preventinggas flow/pressure from being delivered to the patient.

FIG. 4 provides a representation of a basic respiratory therapy system190 in accordance with the present disclosure, and including some of thecomponents of the system 20 (FIG. 2) described above. In particular, thesystem 190 includes the driver unit 22 and the patient interface 24. Thedriver unit 22, in turn, includes the controller 28 and the electronicvalve 40. The electronic valve 40 regulates gas flow/pressure betweenthe inlet line 30 and the outlet line 32. The controller 28 operates theelectronic valve 40 to provide percussive therapy as described above. Inaddition, the controller 28 can optionally be further programmed tooperate the electronic valve 40 to provide baseline pressure and/orpositive airway pressure (PAP) if desired.

FIG. 5 schematically illustrates an alternative respiratory therapysystem 200 in accordance with the present disclosure. The system 200 isakin to the system 170 (FIG. 3) described above, except that the driverunit 22 is configured for connection to only an air source 202. Thus,only a single connector 110 is provided (as compared to the two or moreconnectors 110 of FIG. 3).

FIG. 6 illustrates another respiratory therapy system 210 analogous tothe system 200, with the driver unit 22 configured for fluid connectiononly to an oxygen source 212.

With the alternative construction of FIG. 7, a respiratory therapysystem 220 is provided that is akin to the system 170 (FIG. 3)previously described, except that the filter 100 (FIG. 3) is eliminated.

FIG. 8 illustrates another respiratory therapy system 230 akin to thesystem 170 of FIG. 3, except that the manifold 80 (FIG. 3) iseliminated. Thus, independent lines are employed to fluidly connect theelectronic valve 40, the secondary electronic valve 172, and the nebflow valve 70 with the inlet line 30. Alternatively, a partial manifoldcan be provided, establishing fluid connections to only some of thevalves (e.g., a manifold establishing fluid connection to only theelectronic valves 40, 172 and the neb flow electronic valve 70).

With the alternative respiratory therapy system 240 of FIG. 9, theoptional pressure regulator 90 (FIG. 3) is eliminated. With thisconstruction, incoming pressure control can optionally be accomplishedby the controller 28 operating the electronic valve(s) 40 and/or 172based on information generated at the patient pressure sensor 67 and/ormanifold pressure sensor 120.

Yet another respiratory therapy system 250 is schematically illustratedin FIG. 10, and again is akin in many respects to the system 170 of FIG.3. Unlike the system 170, however, the driver unit 22 omits thesecondary electronic valve 172 (FIG. 3). With this construction, theelectronic valve 40 can be operated by the controller 28 to providepositive airways pressure (PAP) when desired.

With the alternative respiratory therapy system 260 of FIG. 11,aerosol-related components are removed. Thus, the neb flow valve 70(FIG. 3) and the corresponding auxiliary line 35 (FIGS. 1 and 3) areeliminated. Although FIG. 11 reflects that the nebulizer 34 (FIG. 3) hasalso been eliminated, it will be understood that a separate nebulizerunit (not shown) can be separately provided and fluidly connected to thepatient interface (though not controlled by the driver unit 22).

Yet another alternative respiratory therapy system 270 is schematicallyillustrated in FIG. 12, and again is analogous to the system 170 of FIG.3. With the respiratory therapy system 270, however, the vent electronicvalve 174 (FIG. 3) and related vent line 184 (FIG. 3) is eliminated.Emergency shutoff (under excessive pressure conditions) can beaccomplished by the controller 28 operating the electronic valves 40,172 to their closed state.

With the alternative respiratory therapy system 280 of FIG. 13, theoptional manifold pressure sensor 120 (FIG. 3) is eliminated. Operationof the shutoff electronic valve 174 can be dictated by the controller 28based upon information from the patient pressure sensor 67 and/or inresponse to a user-entered command.

Yet another alternative embodiment respiratory therapy system 290 isschematically shown in FIG. 14. The system 290 is analogous to thesystem 170 (FIG. 3) previously described, except that the display system130 (FIG. 3) is eliminated.

As mentioned above, the patient interface device 24 can assume a widevariety of forms that are useful with the driver unit 22. In mostgeneral terms, any construction capable of delivering gas flow/pressureto the patient is acceptable. The patient interface device 24 can bedisposable, and can include various design features for deliveringrespiratory therapy. In general terms, the patient interface device 24defines at least one lumen (e.g., a dual lumen tubing, two or moresingle lumen tubes, etc.) connected to a handpiece. The flow from thedriver unit 22 (via the outlet line 32) travels through one side of thedual lumen tubing (e.g., the inlet end 150) to the handpiece where it iscombined with entrained ambient air and delivered to the patient via amouthpiece or other component such as a mask connected to the outlet end152. The other side of the dual lumen tubing connects to a pressure portnear the patient end of the handpiece. The pressure port, in turn, isadapted for fluid connection to the patient pressure line 36. In oneembodiment, a patient pressure sensor can be integrated directly intopatient interface device 24, wherein patient interface device 24 wouldonly require a single lumen. In this instance, a means of power to thepatient sensor and a means to transmit data to driver unit 22 can beprovided to the patient interface device 24. If aerosol therapy isdesired, the nebulizer 34 can be fluidly connected to the outlet end 152of the patient interface device 24, with a mouthpiece connected to anopposite side of the nebulizer via a T-connector and wherein fluid flowfrom driver unit 22 can be delivered to nebulizer 34 through a separateport via auxiliary line 35.

Additional internal features optionally incorporated with the patientinterface device 24 include a venturi or venturi-like assembly (e.g., amovable venturi tube or a stationary venturi tube). Alternatively, thepatient interface device 24 can incorporate a non-venturi design, suchas a nozzle with a fixed orifice or a nozzle with a mixing throat and nodiffuser. The patient interface device 24 may or may not include anentrainment valve or an exhalation valve. Even further, other usefulcomponents of the patient interface device 24 can include a dual jetconfiguration with a basic diverter, configurations adapted to implementa coanda effect, and other designs that do not provide for ambient airentrainment. Once again, any or all of these patient interface devicefeatures are optional, and are not required for operation of the system20 in accordance with the present disclosure.

FIGS. 15 and 16 illustrate a first exemplary embodiment of a patientinterface device. In particular, FIG. 15 is an exploded view and FIG. 16is a sectional view of a patient interface device 300. The patientinterface device 300 includes a housing 302 and several componentsdisposed within the housing 302. The patient interface device 300defines several ports, for example, a pulsed air inlet port 304, anentrainment port 306, an outlet connector port 308, an exhaust port 310and a pressure port 312. Pulsed air enters inlet port 304 from driver 22(FIG. 1) and ambient air is drawn into housing 302 though entrainmentport 306. Air flow is then delivered to outlet connector port 308, whichcan be configured to couple to a patient mouthpiece or nebulizer. Airexhaled by a patient travels back through outlet connector port 308 andis exhausted through exhaust port 310. Pressure port 312 can be coupledto patient pressure line 36 (FIG. 1) such that pressure in patientinterface device 300 can be measured by driver unit 22 (FIG. 1).

In particular, pulsed air enters inlet port 304 through an end cap 320that includes a connector piece 322 and a central tube 324. End cap 320is positioned within an internal bore 325 provided in housing 302.Connector piece 322 can be connected to outlet line 32 (FIG. 1). Inletport 304 is fluidly coupled to central tube 324 to deliver air thereto.A flexible diaphragm 326 establishes a sealed fluid pathway from tube324 to a corresponding tube 327 of a retainer 328, which terminates at ajet nozzle 329. From nozzle 329, air then enters a venturi assembly 330.Together, retainer 328 and venturi assembly 330 form a jet pump. The jetpump is slidably disposed within housing 302, movable in aback-and-forth manner relative to inlet port 304 and outlet connectorport 308. A spring 332 biases the jet pump toward inlet port 304 andaway from outlet connector port 308. Additionally, an O-ring 334 isprovided to form a seal between venturi assembly 330 and an innersealing surface 338 of the housing 302. Ambient air can enter housing302 through a one-way check valve 340 disposed in entrainment port 306.The one-way check valve 340 permits inflow of ambient air into theentrainment port 306, but prevents gas flow out from the entrainmentport 306.

With particular reference to FIG. 16, venturi assembly 330 forms anentrainment region 342, a throat region 344 and an expansion region 346for combining air from inlet port 304 and entrainment port 306 anddelivering combined air to a lumen 350 fluidly coupled to outletconnector port 308. In the embodiment illustrated; entrainment region342 defines an inlet opening 352 to inlet port 304 and entrainment port306. Throat region 344 defines a tapered, converging portion that routesflow within venturi assembly 330. Expansion region 346 defines atapered, diverging portion that increases in diameter from the throatregion 344 toward lumen 350, terminating at an outlet opening 356.Although other configurations for venture assembly 330 can be used, inthe venturi assembly 330 illustrated in FIGS. 15 and 16, air flow isrouted through a converging portion to a diverging portion to lumen 350.

During operation, pulsed gas flow generated by the driver 22 (FIG. 1)enters through inlet port 304. The pulsed air places a force ondiaphragm 326, which flexes to impart a force (i.e., a force directionon the throat region in a rightward direction relative to FIG. 16) onthe jet pump (i.e. retainer 328 and venturi assembly 330). Pulsed airenters the sliding venturi assembly 330 at the jet nozzle 329. Moreparticularly, airflow from the jet nozzle enters the entrainment region342 wherein throat region 344 creates a vacuum that in turn draws inambient air via the entrainment port 306. The combined pulsed andambient air is directed into the throat region 344. As the force of theflexing diaphragm 326 compresses the spring 332, the sliding jet pumpslides or moves toward the outlet connector port 308. Sliding movementcontinues until a leading end of the venturi assembly 330 (i.e., O-ring334 carried by the venturi assembly 330) contacts and seals againstinner sealing surface 338 of the housing 302. In this sealed position,then, the airflow/pressure pulse is effectively delivered to the outletconnector port 308 and thus the patient. Also, the venturi assembly 330effectively closes the exhalation port 310 in the sealed position. Asthe force on the diaphragm 326 is reduced (i.e., at the end of thepressure pulse), the diaphragm 326 and spring 332 force the venturiassembly 330 away from the inner sealing surface 338, opening thepathway between the outlet connector port 308 and the exhalation port310. Thus, the patient can easily exhale through the outlet connectorport 308 and the exhalation port 310 (i.e., the sliding jet pump doesnot directly resist exhaled airflow from the patient when moved from thesealed position).

In a further embodiment, housing 302 includes a progressive seal 358(FIG. 15) that is formed of a cut-out section of the housing 302. Theprogressive seal 358 is tapered to prevent immediate sealing betweenoutlet connector port 308 and ambient (i.e. through exhalation port310). That is to say, the size of the orifice of the seal 358 decreasesas venturi assembly 330 approaches inner sealing surface 338. Thus,sealing between outlet connector port 308 and ambient occurs gradually.

In an alternative embodiment, the exhalation valve can be separate fromthe venturi assembly. In this case, increased control of the exhalationvalve can be provided as well as allowing for a fixed venturi assembly.In still a further embodiment, the exhalation valve can be eliminated.

The outlet connector port 308 can be configured to receive either apatient mouthpiece or a nebulizer (it being understood that theso-connected nebulizer can in turn carry a patient mouthpiece).Connection of the nebulizer (e.g. nebulizer 34 of FIG. 1) is downstreamof the venturi assembly 330 and the entrainment port 306. That is tosay, flow from the nebulizer via the outlet connector port 308 is notsimultaneously entrained into the pulsed air flow with ambient air.Instead, nebulized medication is delivered directly to the patient,carried by the previously-combined pulsed gas flow and entrained ambientair. By locating the nebulizer downstream from the outlet connector port308, particle knock-down of aerosoled medication within patientinterface device 300 is reduced. In particular, medication knock-downwithin patient interface 300 is prevented, allowing more respirable massto reach the patient. For example, a percentage of respirable medication(e.g. Albuterol) in mass delivered to a patient can be several timesgreater (e.g. five times or more) when locating the nebulizer downstreamof the connector port, as opposed to directly entraining medicationwithin housing 302.

Exhalation port 310, as illustrated, includes openings 359 to preventexhalation port 310 from easily being inadvertently sealed, for exampleby a person's hand or finger. Additionally, a suitable filter (notshown) can be positioned within exhalation port 310 to filter unwantedcontaminants from reaching the caregiver. The filter can take variousforms such as bacterial, HEPA, viral, etc.

Pressure port 312 can be provided with suitable connection means 360that connects to patient pressure line 36 (FIG. 1). As discussed above,driver 22 can measure pressure in the patient pressure line 36 throughuse of pressure sensor 67. The measured pressure can be used to controlthe one or more valves associated with driver 22. When patient pressureline 36 is purged, fluid exits into lumen 350. Since nebulizer 34 can belocated downstream of patient interface device 300, patient pressureline 36 may have increased medicament deposition therein. Thus, purgingpatient pressure line 36 can be advantageous.

FIG. 17 illustrates a second exemplary embodiment of a patient interfacedevice 400. The patient interface device 400 includes similar componentsto the patient interface device 300 illustrated in FIGS. 15 and 16.Additionally, patient interface device 400 includes a nebulizer port 402directly integrated with outlet connector port 308. In this manner, anebulizer can be fluidly coupled directly to patient interface device400 through nebulizer port 402 and downstream from venturi assembly 330.The integrated nebulizer port 402 provides a fixed relation to venturiassembly 330 and a quick setup for a caregiver to insert a compatiblenebulizer and reduces dead volume, thereby increasing efficiency of thesystem.

FIGS. 18-20 illustrated a third embodiment of a patient interface device500. Patient interface device 500 includes several of the samecomponents as patient interface device 300 (FIGS. 15-16) wherein similarcomponents are similarly numbered. As with patient interface device 300,patient interface device 500 includes a housing 502 defining an inletport 504 and an outlet connector port 508. However, instead of havingseparate ports for entrainment and exhaust, housing 502 includes aunitary exhaust/entrainment port 510 positioned along a length of thehousing 502. During operation, air can be entrained into unitary port510 through an entrainment portion 510 a of unitary port 510 (i.e.upstream of venturi assembly 330) and exhausted through an exhalationportion 510 b (i.e. downstream of venturi assembly 330). As illustratedin FIG. 19, if desired, a filter (e.g. bacterial, HEPA, viral) 512 canbe positioned within unitary port 510 to prevent unwanted contaminantsfrom entering housing 502.

FIG. 20 is a sectional illustration of patient interface device 500,showing several components disposed within housing 502. Elements withinhousing 502 operate similarly elements in housing 302 and areillustrated similarly in FIG. 20, for example, pressure port 312,diaphragm 326, retainer 328, nozzle 329, venturi assembly 330, spring332, O-ring 334, inner sealing surface 338 and lumen 350. In FIG. 20, aprogressive seal 558 is cut out of an internal portion of the housing502. In particular, the progressive seal 558 is formed in inner sealingsurface 338 and operates similar to progressive seal 358 of FIG. 15.Also, a connection means 560 is formed integrally with housing 502 andobliquely oriented with respect to an axis coaxial with respect to inletport 504 and outlet connector port 508.

FIG. 21 is an illustration of an exemplary connector 600 configured tocooperate with a connector block 602 of a driver unit. Connector 600 canbe used to quickly connect a patient interface device to a driver unit.Connector 600 includes ports 604, 606 and 608 that are fluidly connectedto corresponding apertures 610, 612 and 614 of connector block 602.Furthermore, ports 604, 606 and 608 can be fluidly coupled to patientpressure line 36, outlet line 32 and auxiliary line 35, respectively.Once lines 32, 35 and 36 are connected to connector 600, ports 604, 606and 608 can be positioned within apertures 610, 612 and 614.Additionally, connector 600 includes tabs 620 and 622 that cooperatewith tab receiving portions 630 and 632, respectively. Tabs 620 and 622can be resilient members that can be pressed towards each other andinserted into tab receiving portions 630 and 632. Hooks at the end ofthe tabs 620, 622 can then engage the tab receiving portions 630, 632such that connector 600 is secured to connector block 602.

Although the present disclosure has been described with respect topreferred embodiments, workers skilled in the art will recognize thatchanges can be made in form and detail without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A method for delivering respiratory therapy to apatient, comprising: delivering pressurized gas flow to an inlet port ofa housing; drawing in ambient air from an entrainment port in thehousing; combining the pressurized gas flow with the ambient air using ajet pump disposed within the housing; delivering combined air from thejet pump to a nebulizer; introducing medication into the combined airusing the nebulizer; forming a seal between the jet pump and an innersealing surface of the housing to close a flow path between anexhalation port and an outlet port of the housing; progressivelyoccluding a cut-out through the housing, between the exhalation port andthe inner sealing surface, as the jet pump moves toward the innersealing surface; and delivering medicated gas flow to the patient. 2.The method of claim 1, comprising exhausting air flow received from thepatient through the exhalation port.
 3. The method of claim 1, andfurther comprising: combining the pressurized gas flow with the ambientair in an entrainment region of the jet pump; forcing the combined airthrough a throat region of the jet pump; and delivering the combined airto an expansion region of the jet pump.
 4. The method of claim 1,wherein a spring biases the jet pump with respect to the housing in adirection toward the inlet port.
 5. The method of claim 1, wherein asthe jet pump moves away from the outlet port, a flow path is createdbetween the exhalation port and the outlet port.
 6. The method of claim1, wherein the housing includes a nebulizer port fluidly coupling thenebulizer to the housing.
 7. The method of claim 1, wherein the cut-outis defined through the housing and tapers toward the outlet port.
 8. Amethod for delivering respiratory therapy to a patient, comprising:delivering pressurized gas flow to an inlet port of a housing; drawingin ambient air from an entrainment port in the housing; combining thepressurized gas flow with the ambient air using a jet pump slideablydisposed within the housing; delivering combined air from the jet pumpto an outlet port in the housing; and forming a seal between anexhalation port and the outlet port when the jet pump engages against aninner sealing surface of the housing, wherein forming the sealprogressively occludes a cut-out through the housing, between theexhalation port and the inner sealing surface of the housing, as the jetpump moves toward the inner sealing surface outlet port.
 9. The methodof claim 8, wherein the cut-out through the housing is tapered towardthe outlet port.
 10. The method of claim 8, further comprisingexhausting, via the exhalation port, air flow received from the outletport.
 11. The method of claim 8, further comprising: combining thepressurized gas flow with the ambient air in an entrainment region ofthe jet pump; forcing the combined air through a throat region of thejet pump; and delivering the combined air to an expansion region of thejet pump.
 12. The method of claim 8, wherein a spring biases the jetpump with respect to the housing in a direction toward the inlet port.13. The method of claim 8, wherein as the jet pump moves away from theoutlet port, a flow path is created between the exhalation port and theoutlet port.
 14. The method of claim 8, wherein the housing includes anebulizer port fluidly coupling a nebulizer to the housing.
 15. Themethod of claim 8, wherein as the jet pump moves away from the outletport, an orifice of the cut-out is progressively unblocked.